全文获取类型
收费全文 | 314篇 |
免费 | 14篇 |
国内免费 | 125篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 23篇 |
环保管理 | 33篇 |
综合类 | 202篇 |
基础理论 | 46篇 |
污染及防治 | 99篇 |
评价与监测 | 11篇 |
社会与环境 | 12篇 |
灾害及防治 | 16篇 |
出版年
2023年 | 5篇 |
2022年 | 19篇 |
2021年 | 16篇 |
2020年 | 12篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 16篇 |
2016年 | 9篇 |
2015年 | 20篇 |
2014年 | 26篇 |
2013年 | 41篇 |
2012年 | 39篇 |
2011年 | 23篇 |
2010年 | 21篇 |
2009年 | 35篇 |
2008年 | 20篇 |
2007年 | 16篇 |
2006年 | 22篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 14篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1986年 | 3篇 |
1983年 | 1篇 |
排序方式: 共有453条查询结果,搜索用时 31 毫秒
241.
基于RS与GIS功能互补性的震害评估方法浅析 总被引:1,自引:0,他引:1
震害评估是震后对建筑物和生命线工程等易损性,以及对人员伤亡和直接经济损失进行统计评估,实时有效的震灾评估是减少震灾损失的有力途径,意义重大。随着空间遥感技术以及计算机技术和图像处理技术的不断发展,基于数字图像处理的震害评估越来越得到广泛应用。在对RS和GIS技术的介绍的基础上,探讨了二者在震灾评估功能上的互补性,并以特定的方式相结合,建立了由四模块组成的基于RS和GIS的建筑物震害评估系统,得出基于震害提取的损失评估方法。基于震害指数的粗略评估和基于RS图像分类的精细评估方法结合运用,可以实时地、较准确地对建筑物震害损失进行评价。 相似文献
242.
243.
Shang Wang Weiguo Hou Hongchen Jiang Liuqin Huang Hailiang Dong Shu Chen Bin Wang Yongcan Chen Binliang Lin Ye Deng 《环境科学学报(英文版)》2021,33(3):156-167
Organic and inorganic materials migrate downstream and have important roles in regulating environmental health in the river networks. However, it remains unclear whether and how a mixture of materials (i.e., microbial species) from various upstream habitats contribute to microbial community coalescence upstream of a dam. Here we track the spatial variation in microbial abundance and diversity in the Three Gorges Reservoir based on quantitative PCR and 16S rRNA gene high-throughput sequencing data. We further quantitatively assess the relative contributions of microbial species from mainstem, its tributaries, and the surrounding riverbank soils to the area immediately upstream of the Three Gorges Dam (TGD). We found an increase of microbial diversity and the convergent microbial distribution pattern in areas immediately upstream of TGD, suggesting this area become a new confluence for microbial diversity immigrating from upstream. Indeed, the number of shared species increased from upstream to TGD but unique species decreased, indicating immigration of various sources of microbial species overwhelms local environmental conditions in structuring microbial community close to TGD. By quantifying the sources of microbial species close to TGD, we found little contribution from soils as compared to tributaries, especially for sites closer to TGD, suggesting tributary microbes have greater influence on microbial diversity and environmental health in the Three Gorges Reservoir. Collectively, our results suggest that tracking microbial geographic origin and evaluating accumulating effects of microbial diversity shed light on the ecological processes in microbial communities and provide information for regulating aquatic ecological health. 相似文献
244.
Wu Long Shang Zhongsheng Wang Hui Wan Wenjie Gao Xinyuan Li Zhanyong Kobayashi Noriyuki 《Journal of Material Cycles and Waste Management》2018,20(3):1676-1688
Journal of Material Cycles and Waste Management - Low-cost and effective activated carbon for copper ion adsorption was prepared from walnut shell by CO2 activation in a fluidized bed. The effects... 相似文献
245.
Effects of biofilter media depth and moisture content on removal of gases from a swine barn 总被引:1,自引:0,他引:1
Tongshuai Liu Zhiping Zhu Bin Shang Fubin Yin Wanqin Zhang 《Journal of the Air & Waste Management Association (1995)》2017,67(12):1288-1297
Media depth (MD) and moisture content (MC) are two important factors that greatly influence biofilter performance. The purpose of this study was to investigate the combined effect of MC and MD on removing ammonia (NH3), hydrogen sulfide (H2S), and nitrous oxide (N2O) from swine barns. Biofiltration performance of different MDs and MCs in combination based on a mixed medium of wood chips and compost was monitored. A 3 × 3 factorial design was adopted, which included three levels of the two factors (MC: 45%, 55%, and 67% [wet basis]; MD: 0.17, 0.33, and 0.50 m). Results indicated that high MC and MD could improve NH3 removal efficiency, but increase outlet N2O concentration. When MC was 67%, the average NH3 removal efficiency of three MDs (0.17, 0.33, and, 0.50 m) ranged from 77.4% to 78.7%; the range of average H2S removal efficiency dropped from 68.1–90.0% (1–34 days of the test period) to 36.8–63.7% (35–58 days of the test period); and the average outlet N2O concentration increased by 25.5–60.1%. When MC was 55%, the average removal efficiency of NH3, H2S, and N2O for treatment with 0.33 m MD was 72.8 ± 5.9%, 70.9 ± 13.3%, and –18.9 ± 8.1%, respectively; and the average removal efficiency of NH3, H2S, and N2O for treatment with 0.50 m MD was 77.7 ± 4.2%, 65.8 ± 13.7%, and –24.5 ±12.1%, respectively. When MC was 45%, the highest average NH3 reduction efficiency among three MDs was 60.7% for 0.5 m MD, and the average N2O removal efficiency for three MDs ranged from –18.8% to –12.7%. In addition, the pressure drop of 0.33 m MD was significantly lower than that of 0.50 m MD (p < 0.05). To obtain high mitigation of NH3 and H2S and avoid elevated emission of N2O and large pressure drop, 0.33 m MD at 55% MC is recommended.
Implications: The performances of biofilters with three different media depths (0.17, 0.33, and 0.50 m) and three different media moisture contents (45%, 55%, and 67% [wet basis]) were compared to remove gases from a swine barn. Using wood chips and compost mixture as the biofilters media, the combination of 0.33 m media depth and 55% media moisture content is recommended to obtain good reduction of NH3 and H2S, and to simultaneously prevent elevated emission of N2O and large pressure drop across the media. 相似文献
246.
Ping Li Xinbin Feng Guangle Qiu Lihai Shang Guanghui Li 《Environmental geochemistry and health》2009,31(6):683-691
The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure
for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province,
Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 μg/g and 1.9 ± 0.9 μg/g for T-Hg and
Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 μg/g and 1.2 ± 0.5 μg/g for T-Hg and Me-Hg,
respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents,
respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with
higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high
levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the
Wanshan Hg mining area. 相似文献
247.
248.
H. Vandenhove G. Olyslaegers N. Sanzharova O. Shubina E. Reed Z. Shang H. Velasco 《Journal of environmental radioactivity》2009
There is increasing interest in radiological assessment of discharges of naturally occurring radionuclides into the terrestrial environment. Such assessments require parameter values for the pathways considered in predictive models. An important pathway for human exposure is via ingestion of food crops and animal products. One of the key parameters in environmental assessment is therefore the soil-to-plant transfer factor to food and fodder crops. The objective of this study was to compile data, based on an extensive literature survey, concerning soil-to-plant transfer factors for uranium, thorium, radium, lead, and polonium. Transfer factor estimates were presented for major crop groups (Cereals, Leafy vegetables, Non-leafy vegetables, Root crops, Tubers, Fruits, Herbs, Pastures/grasses, Fodder), and also for some compartments within crop groups. Transfer factors were also calculated per soil group, as defined by their texture and organic matter content (Sand, Loam, Clay and Organic), and evaluation of transfer factors' dependency on specific soil characteristics was performed following regression analysis. The derived estimates were compared with estimates currently in use. 相似文献
249.
Youguo Gong Min Hu Yafang Cheng Hang Su Dingli Yue Feng Liu A. Wiedensohler Zhibin Wang H. Kalesse Shang Liu Zhijun Wu Kaitao Xiao Puchun Mi Yuanhang Zhang 《Atmospheric environment (Oxford, England : 1994)》2010,44(27):3278-3285
The coagulation sink and its role in new particle formation are investigated based on data obtained during the PRIDE-PRD2004 campaign at Xinken of Pearl River Delta, China. Analysis of size distributions and mode contributions of the coagulation sink show that the observed higher load of accumulation mode particles impose a significant effect on the coagulation sink and result in higher coagulation sinks at Xinken despite of the lower total particle number compared with other areas. Hence it is concluded that the higher coagulation sink may depress the occurrence frequency of new particle formation events. The strategies targeting at controlling accumulation mode particles may have influences on the frequency of new particle formation events at this area. The factors affecting the coagulation sink are evaluated. The relatively lower ambient relative humidities may weaken the coagulation sink and facilitate the occurrence of new particle formation events during noontime, while the surmise of nucleation and growth involving organic matter may imply an actually higher coagulation sink than expected. These factors have a significant influence on the ultimate fate of the newly formed nuclei and new particle formation. A comparison of event and non-event days indicates that the coagulation sink is not the only decisive factor affecting new particle formation, other factors including the precursor vapors and photochemical activity are none the less important either. Competition of coagulation sink and high source rate leads to the occurrence of new particle formation events at Xinken. 相似文献
250.
1,1-二氯乙烯降解菌的分离鉴定及降解特性 总被引:2,自引:1,他引:1
从好氧活性污泥中分离得到一株能以1,1-二氯乙烯(1,1-DCE)作为惟一碳源和能源生长的革兰氏阴性菌株D-B,经鉴定属于产碱杆菌属(Alcaligenessp.)。当维持菌株D-B浓度一定时,1,1-DCE的去除率随着1,1-DCE浓度的增大先增加后降低,且降解过程主要发生在加入1,1-DCE后的3~5 h内。当1,1-DCE的初始浓度为300μg/L时去除率达到最大值85.32%。菌株D-B对1,1-DCE的降解符合Monod方程,饱和常数Ks=21.96 mg/L,1,1-DCE的最大比基质降解速率Vmax=50.76 mg/(L.h)。 相似文献